Liquid crystal composition and information display apparatus using the liquid crystal composition

ABSTRACT

A liquid crystal composition comprising 5 to 99 % by weight of a liquid-crystalline copolymer, which has both an alkyl chain and a siloxane chain in its main chain, and 1 to 95 % by weight of a low molecular weight liquid-crystalline compound operates at a wide range of temperatures including room temperature, has an excellent film formability, is easy to orient to a high degree by mechanical orientation methods including bending orientation method and responds to the change of electric field at a high speed.

This application is a divisional application Ser. No. 866,343, filedApr. 19, 1992, U.S. Pat. No. 5,316,693.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a liquid crystal composition suitablefor the use in various liquid crystal devices, including liquid crystaldisplay devices, liquid crystal optical devices and liquid crystalmemory devices. The present invention further relates to an informationdisplay apparatus which uses the liquid crystal composition and issuitable for displaying news or advertisement.

(b) Description of the Related Art

As liquid crystal compositions for the use in liquid crystal devices,there were proposed polymer liquid crystal compositions that comprisepolymer liquid-crystalline compounds containing asymmetric carbon atomsand low molecular weight liquid-crystalline compounds [Japanese PatentApplication Kokai Koho (Laid-open) No. 63-84291]. However, since theside-chain polymer liquid-crystalline compounds exemplified therein havegeneral alkylate or siloxane main-chains which provide insufficientspacing between adjacent side-chains, increasing the molecular weightprevents sufficient mixing of low molecular weight liquid-crystallinecompounds for increasing the response speed. This makes it difficult toendow the compositions with a high speed responsibility whilemaintaining the intrinsic polymeric properties. There is another problemthat the temperature range of chiral smectic C phase is so narrow thateven the mixing of the low molecular weight liquid-crystalline compoundshas difficulty in providing liquid crystal compositions operable at awide range of temperatures including room temperature.

As to information display apparatuses, there was proposed a displaycomprising a liquid crystal display, a memory member for memorizing thesubstance of display, a control member for interface, a connector memberfor connecting with a host processor and a battery member for supplyingelectric force [Japanese Patent Application Kokai Koho (Laid-open) No.64-70793]. After separated from the host processor, the display continueto display the display substance. It, however, involves problems thatseparation of the host processor necessitates supply of electric forceto activate the memory part to perform display, that each time thedisplay substance is changed, connection with the host processor isrequired, and increasing the display area is difficult due to the use ofthe conventional liquid crystal display.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a liquid crystalcomposition which functions at a wide range of temperatures includingroom temperature, has excellent formability into film, can be orientedto a high degree by mechanical orientation methods, such as a bendingorientation, is capable of tilt angle (2θ) control, and responses to thechange of electric field at a high speed.

Another object of the present invention is to provide an informationdisplay apparatus which enables display on a large surface or a curvedsurface, can display a variety of substance with a simple drivingcontrol circuit, is resistant to mechanical shock, and requires noexternal power supply and can be made thinner and lighter.

As the result of study for solving the above-described problems, theinventors found that the problems can be solved by liquid crystalcompositions obtained by mixing liquid-crystalline copolymers havingboth alkyl chains and siloxane chains in main-chains with low molecularweight liquid-crystalline compounds in a specific ratio, and the findingled the inventors to complete the present invention.

That is, the present invention provides a liquid crystal compositionwhich comprises

a liquid-crystalline copolymer selected from (a) a liquid-crystallinecopolymer comprising a repeating unit represented by the followingformula [I] ##STR1## wherein each of a and b is an integer of 2 to 5, dis an integer of 0 to 3, e is an integer of 1 to 20, and R¹ is ##STR2##R² is --COOR³, --OR³ or --OCOR³, R³ is ##STR3## * indicating anasymmetric carbon atom, each of R⁴ and R⁵ being methyl group or ahalogen atom, f being an integer of 0 to 10, g being an integer of 0 or1 and h being an integer of 1 to 11 with the proviso that when R⁵ ismethyl group, h is not an integer of 1, and

(b) a liquid-crystalline copolymer comprising a repeating unitrepresented by the following formula [II] and a repeating unitrepresented by the following formula [III] ##STR4## wherein *, a, b, dand e are as defined above, j is an integer of 0 to 3, k is an integerof 2 to 7, R⁶ is an optically active group represented by the followingformula [IV] or an optically inert group represented by the followingformula [V ] ##STR5## *being as defined above, m being an integer of 0to 3, and n being an integer of 2 to 7,

the repeating unit [II] and the repeating unit [III] being present inthe liquid-crystalline copolymer (b) in a molar ratio [II]/[III] of 1/99to 99/1; and a low molecular weight liquid-crystalline compound, theliquid crystal composition containing 5 to 99% by weight of theliquid-crystalline copolymer based on the total of theliquid-crystalline copolymer and the low molecular weightliquid-crystalline compound.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing illustrating the orienting apparatus used inExamples.

FIG. 2 is a perspective view illustrative of the structure of theinformation display apparatus produced in Example 28.

FIG. 3 is a perspective view illustrative of the structure of theinformation display apparatus produced in Example 29.

PREFERRED EMBODIMENTS OF THE INVENTION

The liquid-crystalline copolymer to be used in the present invention isa liquid-crystalline copolymer comprising the repeating unit representedby the formula [I] or a liquid-crystalline copolymer comprising therepeating units represented by the formulas [II] and [III]. The use ofthe side-chain polymer liquid crystal having both the alkyl chains andthe siloxane chains in main-chains as a liquid-crystalline copolymercomponent provides a liquid crystal composition which functions at awide range of temperatures including room temperature and is excellentin film forming properties and in capability of orientation.

Preferred weight average molecular weight (Mw) of the liquid-crystallinecopolymer is at least 1000, more preferably, 1000 to 100,000. Theliquid-crystalline copolymer may be an oligomer liquid crystal, such asa dimer or a trimer.

Some examples of the liquid-crystalline copolymer comprising therepeating unit represented by the formula [I] includes the followingliquid-crystalline copolymers comprising the following repeating units:

(a) a liquid-crystalline copolymer comprising the repeating unitrepresented by the following formula ##STR6## (b) a liquid-crystallinecopolymer comprising the repeating unit represented by the followingformula ##STR7## (c) a liquid-crystalline copolymer comprising therepeating unit represented by the following formula ##STR8## (d) aliquid-crystalline copolymer comprising the repeating unit representedby the following formula ##STR9## (e) a liquid-crystalline copolymercomprising the repeating unit represented by the following formula##STR10## (f) a liquid-crystalline copolymer comprising the repeatingunit represented by the following formula ##STR11## (g) aliquid-crystalline copolymer comprising the repeating unit representedby the following formula ##STR12## (h) a liquid-crystalline copolymercomprising the repeating unit represented by the following formula##STR13## (i) a liquid-crystalline copolymer comprising the repeatingunit represented by the following formula ##STR14## (j) aliquid-crystalline copolymer comprising the repeating unit representedby the following formula ##STR15## (k) a liquid-crystalline copolymercomprising the repeating unit represented by the following formula##STR16## (1) a liquid-crystalline copolymer comprising the repeatingunit represented by the following formula ##STR17## (m) aliquid-crystalline copolymer comprising the repeating unit representedby the following formula ##STR18## (n) a liquid-crystalline copolymercomprising the repeating unit represented by the following formula##STR19##

The liquid-crystalline copolymer comprising the repeating unitrepresented by the formulas [II] and [III] to be used in the presentinvention comprises the repeating unit [II] and the repeating unit [II]in a molar ratio ([II]/[III]) of 1/99 to 99/1, preferably, in a molarratio ([II]/[III]) of 40/60 to 95/5. Preferred liquid-crystallinecopolymers comprising the repeating units represented by the formulas[II] and [III] are those wherein a is an integer of 2 or 3, b is aninteger of 5-a, d is 0 or 1 and e is an integer of 2 to 20.

Typical examples of the liquid-crystalline copolymer comprising therepeating units [II] and [III] are those two represented by thefollowing formulas:

a liquid-crystalline copolymer comprising the repeating unitsrepresented by the following formulas ##STR20## and a liquid-crystallinecopolymer comprising the repeating units represented by the followingformulas ##STR21##

As to the low molecular weight liquid-crystalline compound to be used inthe present invention, known low molecular weight liquid-crystallinecompounds may be suitably used. Two or more low molecular weightliquid-crystalline compounds may be used as a mixture in order tocontrol the temperature range wherein the obtained liquid crystalcomposition exhibits liquid crystal phases, the tilt angle of the liquidcrystal composition or the response time to the change of electricfield. It is difficult to limit the molecular weight of the lowmolecular weight liquid-crystalline compound, and the low molecularweight liquid-crystalline compound to be used in the present inventionis a liquid-crystalline compound having no repeating unit in itsstructure and includes a monomer liquid-crystalline compound.

Preferred low molecular weight liquid-crystalline compounds contain inmolecules the same mesogen groups as those of the liquid-crystallinecopolymers contained in the liquid crystal composition since such lowmolecular weight liquid-crystalline compounds enable increasing theresponse characteristics to electric field without decreasing the tiltangle (2θ) of the liquid crystal composition. Herein, the mesogen groupof the liquid-crystalline copolymer means the cyclic part which does notinclude the spacer part and the flexible end group of the side-chain ofthe liquid-crystalline copolymer. Examples of such liquid-crystallinecompounds include

(1) one wherein only its mesogen group is the same as that of theliquid-crystalline copolymer,

(2) one which contains in molecule the same structure as the structureranging from the mesogen group to the flexible end group contained inthe side-chain of the liquid-crystalline copolymer, for example, the lowmolecular weight liquid-crystalline compounds represented by thefollowing formula ##STR22## wherein x is an integer of 6 to 14, j, *, K,R¹ and R⁶ are as defined above, and

(3) a liquid-crystalline monomer constituting the repeating unit of theliquid-crystalline copolymer, that is, when the liquid-crystallinecopolymer is the one comprising the repeating unit [I], the lowmolecular weight liquid-crystalline compounds represented by thefollowing formula ##STR23## wherein a, b, e and R¹ are as defined above,and when the liquid-crystalline copolymer is the one comprising therepeating units [II] and [III], the low molecular weightliquid-crystalline compound represented by the following formula##STR24## wherein a, b, e, j, k and R⁶ are as defined above.

Among the liquid crystal compositions comprising the liquid-crystallinecopolymer and the low molecular weight liquid-crystalline compound whichhave the same mesogen group, particularly preferred are

(A) one wherein the liquid-crystalline copolymer comprises the repeatingunit [I] and R¹ is ##STR25## and the low molecular weightliquid-crystalline compound is a tricyclic monomer constituting therepeating unit [I] of the liquid-crystalline copolymer and representedby the following formula ##STR26## wherein R⁷ is ##STR27## and (B) onewherein the liquid-crystalline copolymer comprises the repeating units[II] and [III], and the low molecular weight liquid-crystalline compoundis a tricyclic monomer constituting the repeating unit [II] of theliquid-crystalline copolymer and represented by the following formula##STR28##

Typical examples of the low molecular weight liquid-crystalline compoundto be used in the present invention include the followings: ##STR29##

As to the typical examples of the combination of the liquid-crystallinecopolymer and the low molecular weight liquid-crystalline compound whichhave the same mesogen group, in the case where the above-describedliquid-crystalline copolymer (k) is used as a liquid-crystallinecopolymer, it is preferable to use one or more of the following lowmolecular weight liquid-crystalline compounds (1) to (3). ##STR30## "x"is preferably an integer of 8 to 12.

The method of mixing the liquid-crystalline copolymer and the lowmolecular weight liquid-crystalline compound is not limited, and may bea direct mixing method or a solution mixing method. For example, by apreferred solution mixing method, after a predetermined amounts ofliquid-crystalline copolymers and low molecular weightliquid-crystalline compounds are introduced in a vessel, are dissolvedin a solvent, such as dichloromethane, and are mixed, the solvent isevaporated out.

The mixing ratio of the liquid-crystalline copolymer to the total of theliquid-crystalline copolymer and the low molecular weightliquid-crystalline compound is 5 to 99% by weight, preferably 10 to 95%by weight. When the ratio of the liquid-crystalline copolymers is lessthan 5% by weight, the film forming properties and the capability oforientation of the liquid crystal composition will be decreased. If itexceeds 99% by weight, the response time to the change of electric fieldwill be increased.

The combination of the liquid-crystalline copolymers and the lowmolecular weight liquid-crystalline compounds is preferably so selectedthat the liquid crystal composition has such a composition as to exhibita ferroelectric liquid crystal phase or an antiferroelectric liquidcrystal phase which has an excellent responsibility to electric field.Although it is difficult to formulate such composition because itdepends on the compounds used, exhibition of a ferroelectric liquidcrystal phase or an antiferroelectric liquid crystal phase can beattained easily by introducing asymmetric carbon atoms into at least onecompound contained in the liquid crystal composition. In particular, theliquid-crystalline copolymers exemplified above exhibit a ferroelectricliquid crystal phase at a wide range of temperatures, and addition ofappropriate low molecular weight liquid-crystalline compounds makes theobtained liquid crystal composition exhibit a ferroelectric liquidcrystal phase at a wide range of temperatures including roomtemperature.

It is also preferable to endow the liquid crystal composition with adichroism by adding dichroic pigments or by using copolymers acopolymerization product of a pigment part and a liquid-crystallinepart.

Suitable examples of the dichroic pigments are known pigments which havebeen used in the conventional guest-host liquid crystal display devices.Typical examples include anthraquinone derivatives, azo derivatives,diazo derivatives, merocyanine derivatives and tetrazine derivatives.These may be used individually or as a mixture of two or more of them.Preferred are black pigments, which increase the contrast easily.

In general, increasing the content of the low molecular weightliquid-crystalline compound improves the characteristics of the liquidcrystal composition in responding to electric field, but sometimesdecreases the film formability of the liquid crystal composition or themechanical strength of liquid crystal display devices. In order toprevent such a bad influence, it is desirable to add 2 to 30% by weightof non-liquid-crystalline polymers into the liquid crystal composition.Some examples of the non-liquid-crystalline polymer compound includepolyacrylic acid, polymethacrylic acid, polyacrylates,polymethacrylates, polyacrylamide, polyvinylalcohols, polyvinylacetate,polycarbonates, polyesters obtainable by condensing dicarboxylic acidderivatives and diol derivatives, polyamides obtainable by condensingdicarboxylic acid derivatives and diamine derivatives, and polyamidesobtainable by condensing dicarboxylic acid derivatives, monoalcohols andmonoamine derivatives. Particularly preferred are acrylic thermoplasticresins, such as PMMA (poly-methyl-methacrylate) and PBMA(polybutyl-methacrylate).

The present invention further provides an information display apparatuscomprising a liquid crystal display device wherein the liquid crystalcomposition of the present invention is disposed between two flexiblesubstrates which bear on surfaces facing each other respectiveelectrodes; a receiving member for receiving, through radio signals fromthe outside, a substance which is to be displayed by the liquid crystaldisplay device; a driving circuit for driving the liquid crystal opticaldevice according to signals sent from the receiving member; and a powersupply member for supplying electric force to the driving circuit.

In the information display apparatus of the present invention, all theliquid crystal display device, the receiving member, the driving circuitand the power supply member are incorporated in a body, and it ispreferable to enclose the whole information display apparatus with aprotecting member, such as a protecting cover.

The information display apparatus comprises the liquid crystalcomposition and the two flexible substrates which bear respectiveelectrodes and support the liquid crystal composition between them. Theflexible substrates may be any ones which have been commonly used inliquid crystal display devices. Some examples include those made ofcrystalline polymers, such as uniaxially or biaxially stretchedpolyethyleneterephthalate, non-crystalline polymers, such aspolysulfones and polyethersulfons, polyolefins, such as polyethylene andpolypropylene, polycarbonates, and polyamides, such as nylons. Theflexible substrates enable the liquid crystal display device to have acurved surface, thereby endowing the liquid crystal display device witha high speed response characteristics and an ability of display on alarge and curved surface. Further, the liquid crystal display device ofthe present invention continues display even after a power supply is cutoff.

The electrodes born on the flexible substrates may be any one commonlyused in liquid crystal display devices. Preferred are transparent onesor semitransparent ones, such as those made of NESA film or ITO film.The electrodes may be of a striped pattern for dot matrix display, apattern for segment display or a combination thereof, depending on thesubstance of display.

The method of disposing the liquid crystal composition between theflexible substrates with electrodes is not particular limited, and maybe a known method. Since flexible substrates are used, the particularlysuitable method for a high productivity is to conduct continuouslyapplication of the liquid crystal composition to the electrode surfaceof one flexible substrate with electrode and lamination of the otherflexible substrate on the applied liquid crystal composition. The liquidcrystal composition in the liquid crystal display device is preferablyso oriented that when the liquid crystal display device is setvertically, or substantially vertically, the liquid crystal compositionexhibiting a smectic phase has a vertical or substantially verticalsmectic layer normal. By this, the visual angle is widened transversely,thereby improving the visibility even when the information displayapparatus is set to trains, busses or the like. The method oforientation is not particularly limited. Preferred method is amechanical orientation method, such as a bending orientation method[Japanese Patent Application Kokai Koho (Laid-open) No. 2-10322] havingexcellent continuous and high speed productivity, since such method doesnot require orientation controlling film, such as rubbing film.

The information display apparatus of the present invention may contain aplurality of liquid crystal display devices. For example, when theproduction apparatus cannot produce liquid crystal display devices ofmore than 30 cm width, lining up three liquid crystal display devices of30 cm width in 3 lines provides an information display apparatus havingan information-displaying surface of 90 cm in width.

The receiving member receives from the outside external radio signals ofthe substance to be displayed by the liquid crystal display device, andit preferably comprises an antenna member and a receiving circuit. Thereceiving member receives a substance transmitted from the outside andthe substance is displayed by the liquid crystal display device.

In order to miniaturize the whole apparatus, the antenna memberpreferably is at most 10 mm in thickness and comprises a flat or curveddielectric sheet bearing a conductor. Preferred conductor is metal foilor metal tape. The antenna member may be further miniaturized by usingloading coils or impedance conversion circuits. When the informationdisplay apparatus is set to moving subjects, such as busses or trains,which vary the direction to the transmitting place, it is preferable touse an antenna with a low directivity and a high gain, such as verticaldipole antennas, diversity antennas, ground plane antennas, sleeveantennas, loop antennas, whip antennas and umbrella antennas. When thefield intensity is sufficiently high, a part of the antenna member maybe connected to the bus body or train body.

As the receiving circuit, any one having a known construction may besuitably used. The system for data transfer is not limited, and in thecase of the use on moving subjects, such as busses and trains, preferredis a frequency-modulated (FM) system which is resistive to theinfluences of external noise.

As to the driving circuit for driving the liquid crystal display deviceaccording to the signals from the receiving member, the same drivingmethods and circuits as those employed for driving low molecular weightferroelectric liquid crystals may be used. Examples of the methodsuitable for dot matrix systems include the methods disclosed inJapanese Patent Application Kokai Koho (Laid-open) No. 1-26543 andJapanese Patent Application Kokai Koho (Laid-open) No. 1-97445. In thecase of segment systems, known methods may also be used suitably.

In the structure of these circuits, conventional driving driver IC forTN cells or various kinds of common IC may be used. When a solar batteryor a thin battery is used as a power supply, it is preferable to useCMOS-IC which consumes very little electricity.

These circuits may be united with the liquid crystal display device in abody.

Examples of the power supply member for supplying electric energy to thedriving circuit suitable for making the whole the apparatus thinner andlighter are those comprising solar batteries or film-form thinbatteries. When solar batteries are used, combining them with propersecondary batteries decreases the influences of the change ofillumination at the place where the information display apparatus isused. Having the power supply member inside the information displayapparatus dispenses with the works for setting up external power supply,thereby enlarging the room for selecting the place for setting. Thepower supply member may be connected to the liquid crystal displaydevice or the receiving member, according to demand.

Examples of suitable solar batteries are those of an inexpensiveamorphous silicon-type. For example, when the driving circuit is aCMOS-IC which requires generally a voltage of approximately 3 V, it isdesirable to use a solar battery generating a voltage required by thecircuit or to supply the required voltage by connecting a plurality ofsolar batteries in series. The change of the output voltage from solarbatteries due to the change of illuminance can be stabilized byequipping with a constant-voltage circuit or by combining with a propersecond battery, such as a nickel-cadmium battery.

Suitable examples other than solar batteries are film-form thinbatteries, which do not destroy the advantages of light weight and thinthickness. Any commercial film-form thin batteries may be suitably used,for example, DENFIL produced by Kimoto Co., Ltd.

Hereinafter, the present invention will be described referring toExamples, which however do not limit the scope of the present invention.

EXAMPLES 1 TO 42 AND COMPARATIVE EXAMPLE 1 EXAMPLES 1 TO 12

Liquid crystal compositions comprising one liquid-crystalline copolymerand one low molecular weight liquid-crystalline compound and exhibitinga ferroelectric liquid crystal phase were prepared by using thefollowing liquid-crystalline copolymers (1) to (4 ) and the followinglow molecular weight liquid-crystalline compounds A to H as indicated inTable 1. Mixing of the liquid-crystalline copolymers and the lowmolecular weight liquid-crystalline compounds was conducted by placingpredetermined kinds and amounts of those in a vessel, dissolving andmixing them at room temperature in 100 ml of dichloromethane addedthereto, and then evaporating out the dichloromethane.

Liquid-crystalline copolymer [1] ##STR31## Synthesis 1: Synthesis of theliquid-crystalline copolymer [1]

[1] Synthesis of ##STR32##

0.1 mol of 1,5-hexadiene-3-ol and 0.17 mol of sodium hydride werestirred in 150 ml of THF for one hour at room temperature. 0.3 mol of1,10-dibromodecane was added thereto, and reflux was carried out for 12hours. After the reaction solution was filtered and concentrated, theconcentrate was purified by column chromatography, to obtain theobjective ether compound (1). (Yield: 63%)

[2] Synthesis of ##STR33##

A solution containing 60 mmol of the ether compound (1) obtained in [1],60 mmol of methyl 4-hydroxybenzoate and 0.2 mol of potassium carbonatedissolved in 150 ml of acetone was refluxed for 12 hours. After thereaction solution was filtered and concentrated, the concentrate waspurified by column chromatography, to obtain the objective ethercompound (2). (Yield: 77%)

[3] Synthesis of ##STR34##

A solution containing 30 mmol of the ether compound (2) obtained in [2],0.1 mol of sodium hydroxide, 50 ml of ethanol and 20 ml of water wasrefluxed for 30 minutes. After the reaction solution was poured into 50ml of water and the mixture was adjusted to pH 2 with a dilute aqueousHCl solution, extraction with ether, drying and concentration werecarried out. The concentrate was purified by column chromatography, toobtain the objective carboxylic acid derivative (3). (Yield: 96%)

[4] Synthesis of ##STR35##

40 g of the carboxylic acid derivative (3) obtained in [3], 34ml ofthionyl chloride and 130 ml of toluene were placed into 1000ml-four-neck flask equipped with a reflux condenser, and were stirred toform a uniform solution. After 0.2 ml of pyridine was added thereto, thereaction temperature was elevated to 65° C., and heating and stirringwere continued for four hours.

Thereafter, the reaction mixture was heated at 65° C. for one hour andfurther at 80° C. for 30 minutes, under a reduced pressure by using anaspirator, to remove out the toluene and the remaining thionyl chloride.After the reaction mixture was cooled to room temperature, 170 ml oftoluene and 11.8 ml of pyridine were added thereto to form a uniformsolution. To the solution was added 170 ml of a toluene solutioncontaining 30.5 g of optically active 1-methylbutyl4'-hydroxybiphenyl-4-carboxylate dropwise over a 30-minutes interval,with stirring. The mixture was stirred overnight at room temperature tocomplete the reaction.

The reaction mixture was filtered to remove out the precipitatedpyridine salt. The filtrate was concentrated by distilling out thesolvent under a reduced pressure at a bath temperature of 5O° C. byusing a rotary evaporator. 80 g of methylene chloride was added to theconcentrate, and stirring was carried out to prepare a uniform andtransparent solution. The solution was then subjected to a fractuationby a liquid chromatography using a pre-column filled with activatedalumina and a main column filled with silica gel. The solvent wasdistilled out from the eluent containing the objective product under areduced pressure at a bath temperature of 50° C. by using a rotaryevaporator, to obtain a crude product of the objective diene compound (4). The crude product was placed in an 1-litter flask, and 900 ml ofethanol was added thereto. The flask was then equipped with a refluxcondenser, and stirring was carried out at 70° C. for 10 minutes. Afterit was confirmed that white solid was completely dissolved to form auniform solution, the flask was allowed to cool near room temperature.After the flask was sealed to shut the humidity out, it was placed in arefrigerator and was allowed to stand for more than 4 hours. The flaskwas then taken out, and the precipitated white solid was collected bysuction filtration and washed with ethanol several times. The solid wasdried overnight in a vacuum drier at 50° C., to obtain 44.4 g of theobjective diene compound (4 ).

The diene compound exhibited liquid-crystalline properties, and had thefollowing phase transition behavior and properties. ##STR36## (Cry:crystal phase, SmA: smectic A phase, S1: an unidentified smectic phase)

Response time: 41 μs (68° C.) Applied electric field: ±20 MV/m

Tilt angle (2θ): 74° (68° C. )

Polyaddition reaction

After 3.85 g of the diene compound (4 ) and 0.54 g oftetramethyldisiloxane were dissolved in toluene, 4.0 mg ofchloroplatinic acid hexahydrate as a catalyst was added thereto in astream of gaseous argon, and reaction was carried out at 80° C. for 20hours.

After the reaction was completed, the reaction mixture was allowed tocool to room temperature, and active carbon was added thereto. Afterstirring for 10 minutes at 50° C., the active carbon was removed out byfiltration. Toluene was distilled out from the reaction mixture under areduced pressure, and the residue was purified by silica gel columnchromatography, to obtain 3.60 g of the objective liquid-crystallinecopolymer.

Liquid-crystalline copolymer. [2] ##STR37## Synthesis 2: Synthesis ofthe liquid-crystalline copolymer [2]

Synthesis of ##STR38##

The same procedure of Synthesis 1 was repeated with the exception that43.2 g of the carboxylic acid derivative (3) obtained in Synthesis 1-[3]and 37.9 g of optically active 1-methylheptyl4'-hydroxybiphenyl-4-carboxylate were used, to obtain 57.8 g of theabove diene compound (5).

The diene compound exhibited liquid-crystalline properties, andexhibited the following phase transition behavior and properties.##STR39## Polyaddition reaction

The same procedure as in Synthesis 1 was repeated with the exceptionthat the diene compound (5) was used, to obtain the objectiveliquid-crystalline copolymer.

1 Liquid-crystalline copolymer [3] ##STR40## Synthesis 3: Synthesis tothe liquid-crystalline copolymer [3]

Synthesis of ##STR41##

The same procedure employed for the synthesis of the diene compound (4 )was repeated with the exception that the same mol number of1-methylheptyl 4-hydroxybenzoate was used in place of 1-methylheptyl4'-hydroxybiphenyl-4-carboxylate.

Polyaddition reaction

14 ml of dried toluene, 1.82 g (2.66 mmol) of the diene compound (4 )obtained above, 0.18 g (0.30 mmol) of the diene compound (6) and 0.26 g(1.94 mmol) of 1,1,3,3-tetramethyldisiloxane were stirred in the streamof gaseous argon, to dissolve them into a uniform solution. After 2.0 mgof chloroplatinic acid hexahydrate was added thereto, heating andstirring were carried out at 80° C. for 20 hours. During the stirring, avery little gaseous argon was continuously flowed through to shut outthe humidity and oxygen from the reaction vessel.

After completion of the polymerization reaction, the reaction mixturewas filtered, and toluene was distilled out from the filtrate. Theobtained residue was diluted with 3 g of methylene chloride, andseparation and purification were carried out by a column chromatographyusing silica gel as a filler, to obtain 1.74 g of the objectiveliquid-crystalline copolymer.

Liquid-crystalline copolymer [4] ##STR42## Synthesis 4: Synthesis to theliquid-crystalline copolymer [4]

Synthesis of ##STR43##

15.0 g (40.0 mmol) of the carboxylic acid derivative (3) obtained inSynthesis 1, 9.52 g (80.0 mmol) of thionyl chloride and 50 ml of driedtoluene were placed in a flask, and were stirred to form a uniformsolution. 0.02 ml of pyridine was added thereto, and stirring wascarried out to form a uniform solution.

The solution was then heated to 65° C., and was heated and stirred for 4hours. Subsequently, toluene and excessive thionyl chloride weredistilled out under a reduced pressure, and 130 ml of toluene and 3.60 gof pyridine were added thereto. A solution containing 7.86 g (35.4 mmol)of 1-n-hexyl 4-hydroxybenzoate dissolved in 130 ml of toluene was addeddropwise thereto over a 30-minutes interval. Stirring was then carriedout for 18 hours at room temperature.

The reaction mixture was filtered and concentrated, and the concentratewas purified by column chromatography using silica gel and alumina asfillers, to obtain 14.7 g of the objective product.

Polyaddition reaction

20 ml of dried toluene, 2.45 g (3.82 mmol) of the diene compound (4),0.55 g (0.95 mmol) of the diene compound (7) and 0.43 g (3.18 mmol) of1,1,3,3-tetramethyldisiloxane were stirred in the stream of gaseousargon, to dissolve them into a uniform solution. After 2.5 mg ofchloroplatinic acid hexahydrate was added thereto, heating and stirringwere carried out at 80° C. for 20 hours. During the stirring, a verylittle gaseous argon was flowed through continuously, to shut out thehumidity and oxygen from the reaction vessel.

After completion of the polymerization reaction, the reaction mixturewas filtered, and toluene was distilled out from the filtrate. Theobtained residue was diluted with 3 g of methylene chloride, andseparation and purification were carried out by a column chromatographyusing silica gel as a filler, to obtain 2.84 g of the objectiveliquid-crystalline copolymer. ##STR44##

The phase transition temperature, the electric field response timeτ₁₀₋₉₀ and THE tilt angle 2θ of the obtained liquid crystal compositionsare shown in Tables 1 and 2. The electric field response time τ₁₀₋₉₀ isthe time which was taken by the change of the transmittance through acell of 2 μm thick between crossed polarizers from 10% to 90% with anapplied voltage of ±10 V at the room temperature, 25° C. The tilt angle2θ is the angle determined by measuring the change of an extinctionangle between crossed polarizers at the room temperature, 25° C.

EXAMPLES 13 TO 17

In the same manner as in Example 1, liquid crystal compositions each ofwhich comprised, as indicated in Table 2, one liquid-crystallinecopolymer and two low molecular weight liquid-crystalline compounds andexhibited a ferroelectric liquid crystal phase were prepared. Theresults are shown in Table 2.

EXAMPLES 18 TO 20

In the same manner as in Example 1, liquid crystal compositions each ofwhich comprised two liquid-crystalline copolymers and one low molecularweight liquid-crystalline compound and exhibited a ferroelectric liquidcrystal phase, as indicated in Table 3, were prepared. The results areshown in Table 3.

EXAMPLE 21

In the same manner as in Example 1, a liquid crystal composition whichcomprised two liquid-crystalline copolymers and two low molecular weightliquid-crystalline compounds and exhibited a ferroelectric liquidcrystal phase, as indicated in Table 3, was prepared. The results areshown in Table 3.

EXAMPLES 22 AND 23

In the same manner as in Example 1, a liquid crystal composition whichcomprised one liquid-crystalline copolymer and one low molecular weightliquid-crystalline compound and exhibited an antiferroelectric liquidcrystal phase, as indicated in Table 3, was prepared. The results areshown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                Low molecular                                                     Liquid-     weight         Phase                                              crystalline liquid-crystalline                                                                           transition             Electric field              copolymer   compound Quantities                                                                          temperature            response                                                                             Tilt angle           Ex. No.                                                                             1  2  1   2    (mg)  (°C.)           τ.sub.10-90                                                                      2 θ                                                                     (°)           __________________________________________________________________________    1     [1]   A        70:30                                                                                ##STR45##             11.6   66                   2     [1]   B        80:20                                                                                ##STR46##             16.3   74                   3     [1]   B        20:80                                                                                ##STR47##             2.1    74                   4     [1]   C        50:50                                                                                ##STR48##             8.2    58                   5     [1]   G        60:40                                                                                ##STR49##             10.5   66                   6     [ 2]  E        80:20                                                                                ##STR50##             4.0    64                   7     [2]   F        60:40                                                                                ##STR51##             0.8    47                   8     [3]   A        70:30                                                                                ##STR52##             12.7   70                   9     [3]   E        70:30                                                                                ##STR53##             2.4    54                   __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________                Low molecular                                                     Liquid-     weight         Phase                                              crystalline liquid-crystalline                                                                           transition             Electric field              copolymer   compound Quantities                                                                          temperature            response                                                                             Tilt angle           Ex. No.                                                                             1  2  1   2    (mg)  (°C.)           τ.sub.10-90                                                                      2 θ                                                                     (°)           __________________________________________________________________________    10    [3]   F        60:40                                                                                ##STR54##             0.58   38                   11    [4]   B        60:40                                                                                ##STR55##             11.8   72                   12    [4]   E        80:20                                                                                ##STR56##             7.9    49                   13    [1]   E   F    70:20:10                                                                             ##STR57##             5.4    49                   14    [1]   B   C    56:14:30                                                                             ##STR58##             10.2   65                   15    [1]   C   F    60:20:20                                                                             ##STR59##             3.9    43                   16    [2]   F   G    60:28:12                                                                             ##STR60##             1.3    51                   17    [3]   E   F    70:20:10                                                                             ##STR61##             3.0    55                   __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________                 Low                                                                           molecular                               Electric                              weight                                  field                    Liquid-      liquid-      Phase                      response                 crystalline  crystalline  transition                 time                     copolymer    compound                                                                             Quantities                                                                          temperature                τ.sub.10-90                                                                    Tilt angle          Ex. No.                                                                             1  2   1  2   (mg)  (°C.)               (ms) 2 θ                                                                     (°)          __________________________________________________________________________    18    [1]                                                                              [2] F      18:42:40                                                                             ##STR62##                 1.4  45                  19    [4]                                                                              [2] F      45:45:10                                                                             ##STR63##                 10.2 65                  20    [ 1]                                                                             [3] E      50:40:10                                                                             ##STR64##                 4    56                  21    [1]                                                                              [2] F  E   15:45:30:10                                                                          ##STR65##                 3    45                  22    [3]    H      40:60                                                                                ##STR66##                 1.7  74                  23    [1]    G      30:70                                                                                ##STR67##                 1.0  57                  __________________________________________________________________________

EXAMPLE 24

The liquid crystal composition prepared in Example 11 was further mixedwith 4% by weight of a black pigment, NKX-1033 (Trade name, produced byNippon Kanko Shikiso Co., Ltd.), and the resulting liquid crystalcomposition exhibited the following phase transition behavior. ##STR68##

The liquid crystal composition had an electric field response timeτ₁₀₋₉₀ of 11.0 ms and a tilt angle 2θ of 71°.

EXAMPLE 25

The liquid crystal composition prepared in Example 14 was further mixedwith 5% by weight of a black pigment LCD-465 (Trade name, produced byNippon Kayaku Co., Ltd.), and the resulting liquid crystal compositionexhibited the following phase transition behavior. ##STR69##

The liquid crystal composition had an electric field response timeτ₁₀₋₉₀ of 9 ms and a tilt angle 2θ of 64°.

EXAMPLE 26

The liquid crystal composition prepared in Example 3 was dissolved intoluene to form a 20% by weight solution, and a PES (polyethersulfone)substrate bearing an ITO electrode (produced by Sumitomo Bakelite Co.,Ltd.) (width: 150 mm, thickness: 100 μm, length: 20 m) was coated withthe solution on the ITO electrode surface by using a micro gravurecoater. After the solvent was drying out, the layer of the liquidcrystal composition had a thickness of about 2.5 μm. Subsequently, thesame kind of substrate not coated with the solution was laminated on thecoated substrate so that the uncoated ITO electrode surface became incontact with the layer of the liquid crystal composition by using tworolls (width 200 mm, diameter: 80 mm, one being made of silicon rubber,the other being made of iron), to form an unoriented device.

By using the orienting apparatus as shown in FIG. 1, the unorienteddevice 1 was oriented by bending it on three rolls 3 (width: 200 mm,diameter: 100 mm, iron rolls), to obtain an oriented device 2. (linespeed v=8 m/min, surface temperatures of the rolls: T₁ =110° C., T₂ =90°C., T₃ =85° C.)

After the orienting treatment, the lengthy oriented device was cut offto a length of 20 cm to obtain an oriented liquid crystal displaydevice. When the liquid crystal display device was arranged betweencrossed polarizers and a direct current voltage of ±10 V was appliedbetween the electrodes at 25° C., a color change between black andyellow was observed with a contrast ratio of about 110. In the lightstate, namely when the display was yellow, the yellow color wasextremely uniform all over the surface of the liquid crystal displaydevice.

COMPARATIVE EXAMPLE 1

Production of an unoriented device and orienting treatment were carriedout in the same manner as in Example 26 with the exception that only thelow molecular weight liquid-crystalline compound B was used. Orientationconditions: v=8 m/min, T₁ =100° C., T₂ =85° C., T₃ =80° C . The liquidcrystal layer was approximately 2 μm thick.

When the oriented device was cut off to a length of 20 cm and wasarranged between crossed polarizers and a direct current voltage of ±10V was applied between two electrodes at 25° C. in the same manner as inExample 26, the display color changed between black and light yellow,with a contrast ratio of 30. The light yellow surface in the light statewas covered with strong yellow spots and white spots, which indicatedthat the thickness of the liquid crystal layer was not sufficientlyuniform. By a polarization microscope observation, many zigzag defectswere observed, which indicated that orientation of theliquid-crystalline compound was insufficient in spite of the thinnerliquid crystal layer than that of the liquid crystal display deviceobtained in Example 26.

According to the above, it is apparent that even the liquid crystalcomposition prepared in Example 26 and contained only 20% by weight ofthe liquid-crystalline copolymer is considerably superior in the filmformability and in the ability to be oriented, as compared with lowmolecular weight liquid-crystalline compounds.

EXAMPLE 27

When the liquid crystal display device produced in Example 26 was bentgradually at room temperature (25° C.) in a direction perpendicular tothe bending direction of the orienting treatment, the orientation of theliquid crystal composition was broken when the radius of curvature wasdecreased to 4 cm. Accordingly, 5% by weight of PMMA (Trade-name of apolymethylmethacrylate produced by Wako Junyaku Co., Ltd., weightaverage molecular weight: 120,000) was added to the liquid crystalcomposition, and a 20% by weight toluene solution of the obtained liquidcrystal composition was prepared in the same manner as in Example 26. Aliquid crystal display device was produced and oriented in the samemanner as in Example 26.

The contrast ratio of the obtained liquid crystal display device wasmeasured to be 95. When the liquid crystal display device was bentgradually in a direction perpendicular to the bending direction of theorienting treatment, the orientation of the liquid crystal compositionwas maintained until the radius of curvature was decreased to 2 cm.

The above indicates that when the strength of liquid crystal displaydevices is insufficient due to the small content of liquid-crystallinecopolymers in liquid crystal compositions, addition of a small amount ofnon-liquid-crystalline copolymers improves the strength of the liquidcrystal display devices without largely decreasing the contrast.

EXAMPLE 28

A 25% by weight dichloromethane solution of a liquid crystal compositionwas prepared by dissolving 9.2 g of the liquid crystal compositionprepared in Example 17 and 0.8 g of PMMA (Trade-name of apolymethylmethacrylate produced by Wako Junyaku Co., Ltd., weightaverage molecular weight: 120,000) as a thermoplastic resin in 30 g ofdichloromethane. A PES substrate with a striped ITO electrode (width:300 mm, thickness: 100 μm, length: 10 m, rolled sheet) was coated withthe solution on the ITO electrode surface by using a micro gravurecoater. After the solvent was evaporated out, the coated substrate waslaminated with the same kind of substrate with the exception that thedirection of the stripe of its ITO electrode is perpendicular to that ofthe former one, by using a pair of pressing rolls (width: 500 mm,diameter: 80 mm, one being made of a chromium-plated iron, the otherbeing made of rubber), so that the ITO electrode surface of the uncoatedsubstrate came in contact with the liquid crystal layer. The liquidcrystal layer was approximately 3 μm thick.

Immediately after that, a uniaxially orienting treatment was carried outby using the bending orientation apparatus as shown in FIG. 1 whichcomprised three rolls. All the three rolls were chromium-plated ironrolls of 80 mm diameter, and were spaced out by 1 mm. The line speed wasv=2 m/min, and the surface temperatures of the rolls were adjusted to T₁=90° C., T₂ =80° C. and T₃ =80° C., so that the device was bent whilethe first roll heated the liquid crystal composition rapidly toisotropic phase and the second and third rolls cooled the liquid crystalcomposition to SmA phase. The orienting treatment provided the liquidcrystal composition with a homogeneous orientation wherein the smecticlayer normal extends in the width direction of the liquid crystaldisplay device, that is, in the direction in which the axes of the rollsused in the orienting treatment extended.

After the orienting treatment, and further approximately five minutesafter the adhesive was cured, two liquid crystal display devices of 800mm long were cut out from the lengthy oriented device. The two liquidcrystal display devices were disposed between parallel polarizers, andan information display apparatus as shown in FIG. 2 was produced. Theinformation display apparatus comprised the liquid crystal displaydevices 5, an antenna member 6, a receiving circuit 7, a driving circuit8 and a solar battery 9 which were housed in a plastic protecting case 4in one body. The display area provided by the two liquid crystal displaydevices was 600 mm×800 mm in size. The antenna element 6 was ashortened-type dipole antenna that comprised a sheet of polyimide and acopper foil born on the surface of the polyimide sheet and was 5 mmthick. Signals received by the antenna member 6 are transferred to thereceiving circuit 7 and further to the driving circuit 8, and thedriving signals made by the driving circuit 8 according to the givensignals make the liquid crystal display device 5 display an information.The solar battery 9 used as a power supply was a commercial onecomprising amorphous silicon. The applied voltage was 4.5 V.

Trying display with the information display apparatus confirmed that theinformation display apparatus could sufficiently operate not onlyoutdoors but also indoors with the light from a fluorescent lamp atnight. According to a reflecting method, a contrast ratio of 20 or morewas ensured. Since a thin ferroelectric polymer liquid crystal displaydevice was used and, further, the direction of orientation (the smecticlayer normal) was made vertical, the visibility at a transverse anglewas so excellent as to ensure a contrast ratio of 10 or more and auniform dark blue displaying color up to ±80°.

The information display apparatus was very light and thin with a weightof only 2.1 kg and sizes of 800 mm×1000 mm×20 mm.

When the information display device was laid on its side (a90°-inclination) to examine the visibility from the side in the samemanner as described above, the contrast ratio was decreased below 10 atan angle of ±40° or more, and the displaying color changed graduallyfrom blue to light brown. This indicates apparently that an orientationdirection aligning to a vertical line drawn on a liquid crystal displaydevice is desirable for the information display device of the presentinvention.

EXAMPLE 29

An information display apparatus as shown in FIG. 3 was produced byusing the ferroelectric polymer liquid crystal composition prepared inExample 1. The method of producing a liquid crystal display deviceemployed in this Example was the same as that employed in Example 26. Anorienting treatment was conducted so that when the liquid crystaldisplay device was set vertically in the side wall of the informationdisplay apparatus, the liquid crystal composition in the liquid crystaldisplay device had a vertical smectic layer normal.

Thus obtained liquid crystal display device 5 was arranged on the sideof a protecting case 4 which was cylindrical in shape, 1500 mm indiameter and 400 mm in height, on the top of which an antenna member 6,which was a diversity antenna, and a solar battery 9 were set up. In thecylindrical protecting case 4 were enclosed a receiving circuit and adriving circuit. The referential numeral 10 represents a leg.

When display was performed with the information display apparatus, asatisfactory display was attained both outdoors and indoors. Theflexible substrates enabled display on a curved surface as in thisExample, and will also enable a surprising display. Further, since theorientation direction (the smectic layer normal) of the liquid crystalcomposition was vertical, the visibility at an transverse angle wasexcellent, and in spite of the curved surface, all the displayed letterswere visible and the displayed color was uniform.

Since the whole apparatus consumed very little electricity, the solarbattery was exchanged with a DENFIL (Trade-name of a film battery of 54mm×85 mm×0.5 mm, produced by Kimoto Co., Ltd.) since the whole apparatusconsumed very little electricity. Nonetheless, the apparatus functionedmore than one year. The information display apparatus excluding the legwas very light and weighed only approximately 1.8 kg.

Liquid-crystalline copolymer [5] ##STR70## Synthesis 5: Synthesis of theliquid-crystalline copolymer [5] Polyaddition reaction

The objective liquid-crystalline copolymer was prepared in the samemanner and conditions as in Synthesis 1 with the exception that 1.14 gof 1,1,3,3,5,5,7,7-octamethyltetrasiloxane was used as a silanecompound.

Liquid-crystalline copolymer [6] ##STR71## Synthesis 6: Synthesis of theliquid-crystalline copolymer [6] Polyaddition reaction

The objective liquid-crystalline copolymer was prepared in the samemanner and conditions as in Synthesis 1 with the exception that 4.07 gof the diene compound (5) obtained in Synthesis 2 and 1.14 g of1,1,3,3,5,5,7,7-octamethyltetrasiloxane were used as a diene compoundand a silane compound, respectively. ##STR72##

EXAMPLES 30 TO 34

In the same manner as in Example 1, liquid crystal compositions each ofwhich comprised one liquid-crystalline copolymer and one low molecularweight liquid-crystalline compound and exhibited a ferroelectric liquidcrystal phase, as indicated in Table 4, were prepared. The results areshown in Table 4.

EXAMPLES 35 TO 38

In the same manner as in Example 1, liquid crystal compositions each ofwhich comprised one liquid-crystalline copolymer and two low molecularweight liquid-crystalline compounds and exhibited a ferroelectric liquidcrystal phase, as indicated in Table 4, were prepared. The results areshown in Table 4.

EXAMPLES 89 TO 41

In the same manner as in Example 1, liquid crystal compositions each ofwhich comprised two liquid-crystalline copolymers and one low molecularweight liquid-crystalline compound and exhibited a ferroelectric liquidcrystal phase, as indicated in Table 4, were prepared. The results areshown in Table 4.

EXAMPLE 42

In the same manner as in Example 1, a liquid crystal composition whichcomprised two liquid-crystalline copolymers and two low molecular weightliquid-crystalline compounds and exhibited a ferroelectric liquidcrystal phase, as indicated in Table 4, was prepared. The results areshown in Table 4.

                                      TABLE 4                                     __________________________________________________________________________                Low molecular                                                     Liquid-     weight         Phase                                              crystalline liquid-crystalline                                                                           transition             Electric field              copolymer   compound Quantities                                                                          temperature            response                                                                             Tilt angle           Ex. No.                                                                             1  2  1   2    (mg)  (°C.)           τ.sub.10-90                                                                      2 θ                                                                     (°)           __________________________________________________________________________    30    [1]   I        70:30                                                                                ##STR73##             4.6    33                   31    [1]   F        67:33                                                                                ##STR74##             2.9    47                   32    [1]   D        67:33                                                                                ##STR75##             3.2    45                   33    [3]   K        65:35                                                                                ##STR76##             1.0    51                   34    [5]   F        75:25                                                                                ##STR77##             2.4    47                   35    [1]   E   J    70:20:10                                                                             ##STR78##             3.2    42                   36    [1]   B   F    42:28:30                                                                             ##STR79##             3.0    47                   37    [2]   H   F    40:21:39                                                                             ##STR80##             0.6    45                   38    [2]   B   F    40:20:40                                                                             ##STR81##             1.3    45                   39    [1]                                                                              [2]                                                                              E        40:40:20                                                                             ##STR82##             2.9    55                   40    [1]                                                                              [6]                                                                              F        20:50:30                                                                             ##STR83##             0.9    57                   41    [1]                                                                              [6]                                                                              F        30:40:30                                                                             ##STR84##             1.5    51                   42    [1]                                                                              [6]                                                                              F   L    20:50:20:10                                                                          ##STR85##             2.1    49                   __________________________________________________________________________

As shown in Tables 1 to 4, combining liquid-crystalline copolymers whichwere side-chain polymer liquid crystals having alkyl chains and siloxanechains in main chains and low molecular weight liquid-crystallinecompounds provided easily liquid crystal compositions which wereexcellent in the film formability and the ability to be oriented andhave a high speed response characteristic to electric field.

Also, using low molecular weight liquid-crystalline compounds having thesame mesogen groups as those of the liquid-crystalline copolymerscontained in liquid crystal compositions provided a high speed responsecharacteristic to electric field without a large decrease in the tiltangle 2θ.

What is claimed is:
 1. An information display apparatus, comprising:(a) a liquid crystal display device for displaying a display substance which comprising a liquid crystal composition comprising a liquid crystal copolymer selected from the group consisting of (1) a liquid-crystalline copolymer comprising a repeating unit represented by the following formula (I) ##STR86## wherein each of a, and b is an integer of 2 to 5, d is an integer of 0 to 3, e is an integer of 1 to 20, and R¹ is ##STR87## R² is --COOR³, --OR³ or --OCOR, R³ is ##STR88## * indicating an asymmetric carbon atom, each of R⁴ and R⁵ being a methyl group or a halogen atom, f being an integer of 0 to 10, g being an integer of 0 or 1 and h being an integer of 1 to 11, with the proviso that when R⁵ is a methyl group, h is not an integer of 1, and (2) a liquid-crystalline copolymer comprising a repeating unit represented by the following formula (II) and a repeating unit represented by the following formula (III) ##STR89## wherein *, a, b, d and e are as defined above, j is an integer of 0 to 3, k is an integer of 2 to 7, R⁶ is an optically active group represented by the following formula (IV) or an optically inert group represented by the following formula (V) ##STR90## * being as defined above, m being an integer of 0 to 3, and n being an integer of 2 to 7,the repeating unit (II) and the repeating unit (III) being present in the liquid-crystalline copolymer (2) in a molar ratio (II)/(III) of 1/99 to 99/1; and a low molecular weight liquid-crystalline compound, the liquid crystal composition containing 5 to 99% by weight of the liquid-crystalline copolymer based on the total of the liquid-crystalline copolymer and the low molecular weight liquid-crystalline compound and two flexible substrates sandwiching the liquid crystal composition between them and bearing on their surfaces facing each other respective electrodes, (b) a receiving member for receiving a substance to be displayed, through a radio signal from outside of the information display apparatus, (c) a driving circuit for driving the liquid crystal display device according to a signal from the receiving member, and (d) a power supply member for supplying electric force to the driving circuit.
 2. The apparatus of claim 1, wherein the liquid crystal composition exhibits a ferroelectric liquid crystal phase or an antiferroelectric liquid crystal phase.
 3. The apparatus of claim 1, wherein the liquid crystal composition has a dichroism.
 4. The apparatus of claim 1 further comprising a non-liquid-crystalline polymer.
 5. The apparatus of claim 2, wherein the liquid-crystalline copolymer has a weight average molecular weight of 1,000 to 100,000.
 6. The apparatus of claim 5, wherein the repeating unit (II) and the repeating unit (III) are present in the liquid-crystalline copolymer (b) in a molar ratio (II)/(III) of 40/60 to 95/5.
 7. The apparatus of claim 6, wherein the liquid-crystalline copolymer is selected from the group consisting ofa liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR91## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR92## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR93## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR94## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR95## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR96## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR97## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR98## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR99## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR100## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR101## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR102## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR103## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR104## a liquid-crystalline copolymer comprising repeating units represented by the following two formulas ##STR105## and a liquid-crystalline copolymer comprising repeating units represented by the following two formulas ##STR106##
 8. The apparatus of claim 7, wherein the liquid-crystalline copolymer is selected from the group consisting ofa liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR107## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR108## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR109## a liquid-crystalline copolymer comprising a repeating unit represented by the following formula ##STR110## a liquid-crystalline copolymer comprising repeating units represented by the following two formulas ##STR111## and a liquid-crystalline copolymer comprising repeating units represented by the following two formulas ##STR112## and the low molecular weight liquid-crystalline compound is selected from the group consisting of ##STR113##
 9. The apparatus of claim 6, wherein the liquid-crystalline copolymer is the liquid-crystalline copolymer (1) comprising the repeating unit (I), and the low molecular weight liquid-crystalline compound has the same mesogen group as the liquid-crystalline copolymer (1) has.
 10. The apparatus of claim 9, wherein the liquid-crystalline copolymer (1) comprises the repeating unit (I) wherein R¹ is ##STR114## and the low molecular weight liquid-crystalline compound is a tricyclic monomer constituting the repeating unit (I) of the liquid-crystalline copolymer (1) and represented by the following formula ##STR115##
 11. The apparatus of claim 6, wherein the liquid-crystalline copolymer is the liquid-crystalline copolymer (2), and the low molecular weight liquid-crystalline compound has the same mesogen group as the repeating unit (II) or the repeating unit (III) has.
 12. The apparatus of claim 11, wherein the low molecular weight liquid-crystalline compound is a tricyclic monomer constituting the repeating unit (II) of the liquid-crystalline copolymer (2) and represented by the following formula ##STR116##
 13. The information display apparatus of claim 1, wherein the liquid crystal display device is set substantially vertically, and the liquid crystal composition in the liquid crystal display device exhibits a smectic phase and is so oriented that the smectic phase has a substantially vertical smectic layer normal.
 14. The information display apparatus of claim 1, wherein the liquid crystal display device has a curved display surface.
 15. The information display apparatus of claim 1 which contains a plurality of liquid crystal display devices.
 16. The information display apparatus of claim 1, wherein the power supply member comprises a solar battery or a film-form thin battery.
 17. The information display apparatus of claim 1, wherein the receiving member comprises an antenna member and a receiving circuit, the antenna member being at most 10 mm thick and comprising a flat or curved sheet of a dielectric and a conductor born on a surface of the sheet. 